The present invention relates generally to an article of footwear, and in particular to an article of footwear with a cavity viewing system.
Nakano (U.S. patent application publication number 2008/0263894 A1) teaches a footwear sole that includes a shock absorbing device having an upper plate, a lower plate and a plurality of shock absorbing elements that extend from the plates. The lower plate includes an upper surface, a peripheral edge and a peripheral wall that extends upwardly from the peripheral edge to form a shell. The peripheral wall may be integrally formed with the lower plate and both may be molded from plastic, such as TPU, and formed from a transparent material. The plates and the wall of the device are positioned between the upper and the outsole of the shoe and are retained in the heel region of a top surface of the outsole between an upwardly extending rear wall and a front wall. The surface may alternatively include a midsole or other component between the upper and the outsole. When the device is positioned in the heel region of the outsole, the shock absorbing elements are visible through the peripheral wall and/or the lower plate. Likewise, the plate is exposed, in part, through a cutout portion disposed in the heel region of the outsole.
Wakley (U.S. patent application publication 2007/0113425 A1) teaches a midsole for footwear that includes solid or hollow cushioning tubes. Each tube is the exact width of the midsole so that the tubes are visible from the exterior of the shoe on both of its sides. Both a lower midsole portion and an upper midsole portion have cavities molded in the exact shape of the tubes. The tubes can be open ended at the edge of the midsole or may be enclosed inside a transparent material.
Weiss (U.S. patent application publication 2006/0179683) teaches a pair of inserts for footwear that may be inserted into any portion of the sole but which are preferably inserted into a heel portion. The inserts each have a compressible core and a transparent and flexible casing for surrounding at least a portion of the cores. The cores may include decorative patterns or ribs which are visible through the transparent casing. A portion of the inserts are exposed at any surface, including the bottom, sides and rear of the shoe so that they may be touched. Moreover, the decorative core is visible through the transparent casing from the exterior of the shoe wherever the insert is exposed. The pair of inserts may alternatively be a single larger insert.
The related art lack provisions for providing a low cost alternative to the shock absorbing devices used in a shoe. There is a need for articles that address the limitations of the related art.